Water hammer in condensate lines
Condensate discharged from various steam equipment has different temperatures, and, accordingly, the temperature of the secondary boiling steam. Therefore, water hammer in condensate lines is usually caused by the interaction of low temperature condensate and higher temperature steam. This mainly occurs in the places where the pipelines adjoin the collecting headers.
Mechanism of occurrence of water hammer and methods of their elimination
Here are some of the most illustrative examples.
Places of tie-in pipelines
When the vapor enters the condensate collecting line with cold condensate, instant condensation occurs. If the amount of vapor is small, then small collapses with a small impact force occur, but the problem is constant noise, especially if there are many such areas.
To eliminate it, it is enough to plug the pipeline and make many holes at its end, thereby reducing and dispersing the steam flow.
In horizontal sections, the reverse flow of steam leads to the formation of wave crests, which upon collision form a water hammer.
Reverse steam flow from the condensate line
Reverse flow of steam from the evaporation chamber
To prevent backflow of steam, it is sufficient to install a non-return valve. However, its effectiveness will depend on the correct location.
Formation of large "steam pockets"
This is the most common cause of water hammer in a condensate line. Unlike the previous case, here steam and condensate move in the same direction. And the cause of the blow is in the sharp condensation of the formed steam pocket, and the larger its size, the stronger the blow.
Measures to eliminate the formation of steam pockets:
- replacement of steam traps allowing passage of steam (not to be confused with secondary steam)
- separation of condensate pipelines into high-temperature and low-temperature networks
- avoid tapping into horizontal sections of the condensate pipeline